There was a formal response from Sabaj regarding A20a.
Many A20a on the market are already improved versions.
But when you buy it, you should check with the store.
It is said that replacement parts will be supplied for sold products if requested.
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Dual Merus MA12070 Amplifier Sabaj A20 fully balanced : pictures inside )
- Thread starter daniboun
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Many A20a on the market are already improved versions.
But when you buy it, you should check with the store.
It is said that replacement parts will be supplied for sold products if requested.
The mailman just delivered mine this morning from HiFi-Express via Amazon logistics. I won't be able to evaluate it for a few days. Is there some way to visually determine if it's the revised version?
No. Play some track having mainly deep bass and little to no tweeter sounds (vocals, tromphets) so that you can actually hear through it and turn the volume up. If you can pass -24db without hearing ticking noises from within the case you should be fine. However, I don't think Hifi-Express would still sell the old ones. This shop is in direct contact with the manufacturers, I fact, in believe they are a subsidiary of the manufacturers or at least closely affiliated.
Sabaj has told me that all A20a sold by HiFi-Express are improved versions. So you can rest assured.
SeriousSam70
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I received the A20a a couple of days ago to replace a DA-9 with some wild DC offsets. I have both right now and have been switching them back and forth. The A20a sounds a bit muddier versus the DA-9 that I've been using over the last two weeks. Maybe it just needs 2 weeks of burn-in, but I didn't notice that with the DA-9 when I first got it.
The DA-9 over optical is completely silent at its highest volume. The A20a definitely has a high pitched whine starting at about -8 and very loud at 0. Power supply noise? Is this normal or a bad unit?
I will keep playing the A20a for a week and see if it opens up, but so far I'm not blown away...
The DA-9 over optical is completely silent at its highest volume. The A20a definitely has a high pitched whine starting at about -8 and very loud at 0. Power supply noise? Is this normal or a bad unit?
I will keep playing the A20a for a week and see if it opens up, but so far I'm not blown away...
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I only ever compared mine to my SMSL SA300, and my A20a was slightly cleaner with of course much more power on tap. I had previously been using each over RCA from my Scarlett Solo, which had a relatively high noise floor. White noise starting at around -20 on the A20a. Never heard a high pitch whine on it though. I've since switched to a Topping D10 Balanced and it's dead silent to 0. The whine might be coming from your source.
I have disconnected them both from the source. Same result.
Re: D10 Balanced, I was considering this but didn't see a way of putting in my L30 headphone amp into the mix without a preamp in between. Do you use headphones, too? If so, what is your solution?
Are you using USB to SDAC+02 and optical to D10 Balance/A20a, using the sound settings in the corner of the Windows taskbar to switch between playback?
I read your post and checked my A20a immediately.
At the time of checking, D10s and D10 Balanced are connected to the XLR input and RCA input of A20a, respectively.
With XLR input, it is very quiet up to volume level -10, but after that the noise gradually increases. However, the noise level is such that you cannot hear it unless you bring your ears close to the speaker unit. The noise you hear is like normal white noise.
The RCA input is noisier at the -30 level than the XLR input -00. If you raise the volume level further, the noise level will also rise. If you raise it to -10, you can check the noise without bringing your ears close to the speaker unit. It is noisier than cheap Chinese digital amplifiers. At -00, you can check the noise even if you are 1m away.
Furthermore, I removed the RCA input cable and checked it, but a high frequency sound was added to the noise so far, and when the volume is -00, this high frequency sound can be heard even if it is more than 2 m away.
My guess is that this high frequency sound is a leak of power supply switching noise.
The noise of the A20a is the highest level of noise I have ever experienced. However, I think that there is no problem in practical use up to -20. However, this symptom is not good for both users and manufacturers, so I want you to improve it immediately.
"postscript"
I switched the connection cable to the SMSL AO200 and did a similar test, but the AO200 did not show any of these symptoms.
I raised the volume level to 70 of MAX for both XLR / RCA, but only minute noise. You cannot check it unless you attach your ears to the speaker unit.
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Nope, both on USB! I use Ear Trumpet for way better windows mixer control of apps, as well as the right click being nearly as convenient to switch devices as regular Windows.
Boom, downloaded! SO much better than the Windows mixer. Thank you for the tip!
Hi Toku, thank you for checking on this. Do you think it is worthwhile to send back the A20a and swap it out with the AO200? Are there any differences in sound between the DA-9, A20a, and AO200?
Thanks again for all your help and observations!
Hello,
I have already reported this symptom to Sabaj.
I think that the sound quality of DA-9, AO200, A20a is almost the same. I don't say much because the evaluation of sound quality is completely different for each individual.
The DA-9 has not been repurchased as it has not clearly confirmed subsequent improvements in offset voltage and pop noise issues.
I recommend AO200 if you can return or exchange it. However, if the A20a is not used as a power amplifier with the maximum volume level, I think that there is no problem in daily use.
Very interesting. I just recently swapped my RCA cable connecting Topping E30 with A20a with a more higher grade one that was also shorter. Now I am using a quad shielded cable from WBA, having japan made Canare wires with Amphenol plugs. This one but half the lenght: Link to amazon
Quad-shielded RCA to Sabaj A20a:
edit: No, wait a second. Since my Topping E30 is being fed by the A20a 15v back port via 5v-converter, that would influence the noisefloor too I suppose.
Quad-shielded RCA to Sabaj A20a:
- -20db = ear to speaker = Nothing
- -15db = ear to speaker = Very minimal noise starting to emerge, barely hearable
- -10db = ear to speaker = Intensifies, but still minimal
- -05db = ear to speaker = Now this is noise I would say, but still only hearable if you put your ear to it.
edit: No, wait a second. Since my Topping E30 is being fed by the A20a 15v back port via 5v-converter, that would influence the noisefloor too I suppose.
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Old or new amp ?
Very interesting. I just recently swapped my RCA cable connecting Topping E30 with A20a with a more higher grade one that was also shorter. Now I am using a quad shielded cable from WBA, having japan made Canare wires with Amphenol plugs. This one but half the lenght: Link to amazon
Quad-shielded RCA to Sabaj A20a:
No whining/high frequency noises whatsoever. I am still using the old Sabaj A20a with the active relay though. Maybe the PSU got noisier by changing it. Someone would have to buy a Topping E30 with the same cable that I bought in order to compare with the new A20a.
- -20db = ear to speaker = Nothing
- -15db = ear to speaker = Very minimal noise starting to emerge, barely hearable
- -10db = ear to speaker = Intensifies, but still minimal
- -05db = ear to speaker = Now this is noise I would say, but still only hearable if you put your ear to it.
edit: No, wait a second. Since my Topping E30 is being fed by the A20a 15v back port via 5v-converter, that would influence the noisefloor too I suppose.
What cable ?
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